1. Field of the Invention
The present invention generally relates to a cutter. More particularly, it relates to a cutter haying a blade which is slidably extendable to a protracted cutting position and a retracted storage position.
2. Description of the Prior Art
The following conventional cutters are well known and exemplify the state of the art in the field. A rotary cutter has a disc shaped blade which rotatably and pivotally moves with respect to a stationary handle. A conventional cutter knife has a straight cutting edge. The cutting edge slidably protrudes to permit cutting and is retracted for storage.
The rotary cutter allows the rotational friction force to be adjusted, in order to improve the performance of the cutter. The U.S. Pat. No. 4,301,594 discloses one type of rotary cutter. The cutter has a slider arranged at one end section of a handle. A disc shaped blade is secured to the slider by means of a fastening device, at its center section. Consequently, an appropriate rotational friction force could be applied to the disc blade so as to prevent a free, arbitrary rotation of the disc blade during the cutting operation.
However, when the fastening device is excessively tightened, the rotational friction force is significantly increased. Consequently, the disc blade becomes hard to rotate. When the fastening device becomes loose, the rotational friction force is significantly decreased so that the disc blade starts to freely rotate. As a result, the adjustment of the fastening device becomes rather difficult. If the adjustment is improperly made, the cutting ability of the cutter decreases.
The Japanese Unexamined Utility Model Publication No. 61-54752 discloses a cutter knife which has a straight cutting edge. The cutter knife has a pair of grooves within its handle. The grooves communicate with an outer peripheral end of the elongated handle. One of distal ends of the handle is opened. When a slider is moved along the grooves, the blade is caused to slide by the slider so that the cutting edge of the blade protrudes beyond the distal end of the handle, through the opening in the distal end of the handle.
When the blade is extended by the slider and touches the inner wall of the opening, the sliding ability of the blade significantly decreases. Therefore, it is necessary to create a relatively small gap between the inner wall of the opening and the blade. Consequently, the blade that cannot be securely held in position creates a swaying motion during the cutting operation. As a result, the cutting ability of the blade decreases.